SOME PHYSICAL ASPECTS IN CARDIOVASCULAR DYNAMICS

William Harvey (1628) emphasized that comparative physiologic studies enabled him to understand the essence of blood circulation. This allom etric hemodynamic hypothesis was tested: with growing mass the functio n changes. Cardiovascular dynamics in the whale, elephant, and humming bird were compared. A custom made portable quantitative ballistocardio graph was constructed: the natural frequency was 1000 cps and it regis tered force when the examinee was in the sitting position. A special t ransistor amplifier with a long time constant reduces distortion of fo rm, phase, and time of the registered curves, secured from the VHF-cha ir of 1000 Hz. No damping or isolation from building vibrations was ne cessary. Calibration is in absolute values (Newtons). The weight of th e system is 5.5 kg. Characteristic quantities are systolic force (F) a nd minute cardiac force (MF = F x HR). Examined groups were healthy ob ese children, normal children, adult anorectics, and healthy normals. The minute cardiac force in obese boys was smaller, but not in girls. The systolic force per kg of body weight F kg(-1) in obese boys was sm aller. F in anoretic women is lower, but not in men. MF did not differ in men and women; F kg(-1) is higher in anoretic men and women. The s ame is true for MF kg(-1). Additionally echocardiographic examinations were made in normal (12-14 years) and obese (12-15 years) boys: echo/ Doppler data also showed differences indicating that compliance is low er in obese boys and the maximal flow velocity in the aorta in obese b oys is lower. A close relationship exists between the body mass and va rious cardiovascular dynamics indices.